public enum ContentType
{
    Text,
    Image,
    Video,
    Audio,
}

public class Content
{
    public int Id { get; set; }
    public ContentType { get; set; }
}

public class TestContext : DbContext
{
     public DbSet<Content> Contents { get; set; }

     public static List<Content> GetImages()
     {
          using (var context = new TestContext()
          {
               return context.Contents
                             .Where(c => c.ContentType == ContentType.Image)
                             .ToList();
          }
     }
}